When a composer writes new music for each stanza of poem the form it is known as what?

When a composer writes new music for each stanza of a poem, the form is known as strophic setting.

Here's why:

* Strophic refers to the stanzas of a poem.

* Setting refers to the music composed for the text.

Therefore, a strophic setting indicates that each stanza of the poem has its own unique musical setting, as opposed to a through-composed piece where the music flows continuously without breaks for stanzas.